Centrifuge separators are commonly used to separate lubricants from metal chips or other materials impregnated with lubricating or other fluids. The centrifuge separator device includes a separator bowl with a plurality of spaced blades fixed to the bowl. A substantially cylindrical porous separator screen defined by wire mesh or closely spaced steel bars have openings sufficient to permit passage of lubricant or other fluid therethrough is attached to the top of the bowl.
In a typical operation, metal chips and lubricating fluids to be separated are delivered to the centrifuge. The mixed chips and fluids pass into the rotating separator bowl where the materials are forced outwardly and upwardly along the internal bowl wall and the leading surface of the blades. As the metal chips and fluid pass over the screen, the lubricating fluid separates from the chips as it passes through the screen openings to a lubricating fluid collection chamber. The separated metal chips cannot pass through the screen openings but rather travel upward on the screen surface following which they are blown out of an exit chute to a collecting site.
Unfortunately, separator screens presently used in separator devices are not entirely satisfactory. It has been found that the screens wear relatively quickly as chip materials of certain alloys walk over the screen surface, the chip materials often being quite hard or otherwise abrasive. Indeed, when the centrifuge is operating, the solid material from the fluid travels along the height of the screen contacting the screen surface under heavy pressure created by the action of the centrifuge causing excessive screen wear. One potential solution is to use a harder, more wear-resistant material to fabricate the screen. However, the harder the material, the more difficult and costly it becomes to fabricate the screen. Therefore, any improvement in wear-resistance provided by the harder material may be offset by the increased cost of the screen.
Another disadvantage is that a screen used with a centrifuge separator presently available is relatively costly due to the screen material and the procedure used to make a screen. Screens presently used often are formed by first providing a number of drawn or extruded bars. The bars are notched on the back surface. Thereafter, the notched bars are placed in a form whereby the requisite spacing between bars is carefully arranged to form the desired fluid passage openings. Once the bars are aligned in their appropriate positions, a cross rod is placed in the notches and welded to the bars to complete the screen fabrication. One can appreciate that the time and effort associated with making a screen of this type, often referred to as a "wedge wire" screen, are quite significant such that the screen in a conventional parts separator device constitutes a costly component.
What is desired is to have a screen which has increased wear-resistance over screens presently available. Moreover, it is desired to, if possible, cast or fabricate the screen such that different sizes and shapes of spaces such as slots be provided in the screen without the labor intensive costs presently associated with making conventional screens.